Thermostatic needle control for carburetors



Oct. 27, 1925- E. T. FRANZEN STATIC NEEDLE CONTROL FOR CARBURETORS THERMO t e e & M e 5 a 2 2 5 M Z 8 2 M 1 m w w 3 A MMW 1 m \\l\i\ 3. i: F 4 WOW 1: m W mo 9 J 2 3 Z Z 7 1 IIII/IIIII/IIIIII/II 'IIIIIIIIIIIII'IIIIIIIIII IN VENTOR 57 5M ATTORNEY Oct- 27, 1925.

E. T. FRANZEN THERMOSTATIC NEEDLE CONTROL FOR CARBURETOHS Filed Dec. 4, 1922 2 Sheets-Sheet 2 IN VEN TOR 5 cF/m/n/ZMV A TTORNE Y Patented a. 27, 1925.

UNITED STATES PATENT oFFlcE.

ERIC T. FRANZEN, OF MAPLEWOOD, NEW JERSEY.

THERMOSTATIG NEEDLE CONTROL FOB OABBURETOBS.

application filed December 4, 1922. Serial No. 804,649.

1 provide an improved automatically oper-.

ated, thermostatic needle valve for controllin or throttling the gasoline port in the car uretor. Y

A further purpose is to produce a (lQX'lCC 2 that can be easily substituted for that originally provided, the exchange being made without any change in the carburetor body and by the use of tools readily available.

Another aim is in the production of devices that are adjustable to suit varying conditions in a ready and instant manner.

These and other aims, purposes and objects, Such as compactness, neat appearance and low cost of construction are attained by the'novel design and arrangement ofparts .hereinafter described and shown in the accompanying drawings, forming a material part of this disclosure, and in which:-

Figure 1 is a partial side elevational, partial sectional view of a conventional type of carburetor showing the application of an embodiment of the invention.

Figure 2 is an enlarged longitudinal sectional view. of the preferred form of the control device.-

Figure 3 is an edge view of the same.

Figure 4 is a transverse sectional view taken on line 4-4 of Fig. 2.

Figure 5 is a perspective view of one of the composite thermostatic plates.

Figure 6 is a further enlarged, fragmentary view illustrating the connection between the needle valve plug and its central screw. Figure 7 is a sectional view similar to Fig. 2 but showing a modification in construction.

Figure 8 is another like view illustrating a further modification of the thermostatic elements.

In Fig. 1 of the drawings, the chambered carburetor body is designated by the numeral 15, fed by thesupply pipe 16 from the storage tank, the inlet being controlled by a valve device 17 actuated by the float 18.

Above the body is the valve carrying structure 19, its lower ortion 20 entering nto the body and provided with an openlng 21 communicating between the two portions. An inlet valve 22 admits air to the baflle 23 where it is diverted downwardly, past the opening 21, commin led with the vapor rising from the gaso inc and discharged throu h the throttle valve 24 to the engine inta e or manifold 25, a part of which is indicated at 25 in Fi 1.

On the upper part of the e ement 19, in

register with the opening 21, is a raised boss 26 containing an opening 27, its upper end being usually screw-threaded to receive the adjusting screw by which the aligning openin 21 is controlled, although certain types 0? carburetors have boss externally screw-threaded for the same purpose, these parts not being shown as they are replaced by embodiments of the invention which will now be described.

In the preferred form of the device a casing 30 of the shape shown in Fig. 2 is provided, the same being relatively narrow with flat, parallel sides and having a plug extension 31 to fit the screw-threaded portion of the opening 27, or internally threaded, as at 31' to engage over the boss, as in Fig. 8. v

The upper part of the casing, as shown in Fi 2, is contracted and bored as at 32 to slidably receive a sleeve 33 having flanges 34 extending equally outward from opposite sides at its lower, inner portion, the ends of the flanges having between them recesses 35 into which enters internal lugs 36 extending in from the narrow sides ofthe casing and acting as stops limiting the action of the sleeve 33.

Said sleeve is internally threaded to receive an adjusting screw 37 provided with an extendin head 37 and held when in adjustment fly the knurled lock nut 38 impinging on the top of the sleeve.

The screw-threaded plug 31 or 31' contains a central opening 39 through which passes the stem 40 of the needle plug valve, the same having a conical lower end 41 suited to engage the edge of the opening 21, controlling the passage therethrough.

The upper end of the stem is reduced to form a neck 42 from which extends a spherical element 43 suited to be received in a corresponding seat 44 formed in the lower end of the adjusting screw 37, the surrounding material of which is upset, as at 45, to hold the ball end 43 in place but permitting it to turn and move freely therein, thus allowing the conical point 41 to be centered by the opening 21. i

The thermostatic elements are composed of two metal plates 46 and 47, respectively brass and steel, firmly and permanently united together. bent in the shape of leaf springs tocontact with adjacent elements of the same pair near their outer ends and provided with openings 48 through which the stem 40 freely passes.

As shown in Fig. 2 three pairs are used, the outer or steel surfaces being seated against the flange 34 and bottom of the cas.

ing 30 respectively, said plates being entirely free within the casing.

Opposed to the resilient effect of these thermostatic plates is a helically wound compression spring 49, encircling the sleeve 33 and exerting its pressure between the upper element of the casing 30 and flanges 34, opposite the plates.

Raised from the upper portion of the easings 30 or 30' is a boss 54 bored to tightly receive the lower end of a copper tube 55, the expanded upper end 'of which is located adjacent the outer surface of the manifold 25' so that the air drawn in by pulsations of the motor is heated to a considerable extent when the motor is operating and commingled with the gaseous mixture in the casing prior to entering the manifold.

This hot air acts to increase the effect of the thermostatic couples and conversely, when the manifold is cold, to affect the operation of the couples in an opposite manner, besides adding to the efliciency of the explosive mixture.

In operation, the needle valve being adjusted to its seat, preferably when the parts are warm, to control the flow of vapor rising from the gasoline. it will be understood that if excessive heat be transmitted to the apcasing base, the flanges being pressed down by the spring 49, carrying the sleeve and adjusting screw with it, thus closing the openmg 21.

Upon cooling, the steel elements 47 operate to bend the plates into their original curved shape and thereby raise the flanges 34 and attached parts, opening the valve.

In the modification shown in Fig. 7 the casing 30 is generally rectangular and provided with a flanged sleeve, screw and needle valve of the same type and also the lower set of three thermostatic couples, the same being arranged below the flanges 34.

The compression spring is omitted and in place another set of thermostatic plates are used with the difference that the brass elements 46 are outermost, thus operating re versely tothe lower set, and actuating the valve in a manner clearly apparent.

The flanges 34 are made relatively narrow, the recesses being omitted and in place of the lugs 36,0therinward1y projectinglugs 56, arranged in upper and lower pairs from the narrower sides, contact with the flanges or if preferred the adjacent thermostatic couples as shown.

In Fig. 8 the casing 30 is shaped asinFig. 7 except that as here shown the boss or hub 31 is suited to engage over the extension on the carburetor.

The thermostatic plates 50 and 51 are formed in the manner of loops or return bends and as before, of strips of brass 52 and steel 53, those below the flange 34 having the brass outermost. thus tending to maintain the flanges and attached parts adjustably, moving the same upon any change in temperature, the ultimate movement of the sleeve being controlled by the lugs 56 as previously described.

It will be noted that the device will respond to even slight changes and that the needle can be readily adjusted to control the influx of gasoline in an accurate manner, the needle being entirely free of the plates and self centering in operation.

Although I have described my improvements with considerable detail and with re spect to certain particular forms of my in.- vention, I do not desire to be limited to such details since many changes and modifica tions may well be made without departing from the spirit and scope of my invention in its broadest aspect.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. A carburetor attachment comprising in combination with the mixing chamber and supply chamber thereof, of a closed casing separably engaged with said mixing chamber, means for entering air at variable temperature to said casing, a sleeve slidable through the upper part of said casing, a screw operable in said sleeve, means for locking said 4 screw when in adjustment, a needle valve pivoted in the inner end of said screw, said valve controlling the passage between said chambers, and a series of thern'iostatic cou-- ples in said casing adapted to actuate said sleeve.

2. A carburetor control device comprising a hollow casing reinovably mounted on the' carburetor frame, a sleeve freely slidable therein, a tube having an outer expanded open end, said tube being fixed in the casing, a screw adiustable in said sleeve, a needle valve stem actuated by said screw, a

lurality of thermostatic couples arran d 15 This specification signed this second day 20 of December, 1922.

. ERIC T. FRANZEN, 

